With the expansion of network bandwidth, services are required that handle large amounts of data such as image distribution and the like. As a component technology thereof, OpenFlow in Non Patent Literature 1 and 2 may be cited. In OpenFlow, switches capable of high-speed forwarding are arranged on a user plane, and by optimally setting path information by an OpenFlow controller, it is possible to adequately respond to high speed forwarding needs.    [Non Patent Literature 1]    Nick McKeown and 7 others, “OpenFlow: Enabling Innovation in Campus Networks”, [online], [search conducted Feb. 14, 2012], Internet <URL: http://www.openflow.org/documents/openflow-wp-latest.pdf>    [Non Patent Literature 2]    “OpenFlow 1.2”, [online], [search conducted Mar. 27, 2012], Internet <URL: https://www.opennetworking.org/images/stories/downloads/openflow/openflow-spec-v1.2.pdf>